Synergistic insecticidal compositions



United States Patent-O SYNERGISTIC TNSECTIC-IDAL COMPOSITIONS Howard A. Jones and John A. vGarman, Baltimore, Md.,

and Berton C. Dickinsom'Lyndonville, N.Y., assignors to Food Machinery and Chemical Corporation, New

York, N.Y., a corporation of Delaware No'JDrawing. Original applicatiorfMar. 24, 1955, Ser.

'No. 496,596. Divided and 'this'application Oct. 23,

1958, Ser. No. 769,069

7 Claims. (Cl. 167-22) This invention relates broadly to insecticidal compositions, and more particularly to insecticidal compositions containing an organic carbamate acid derivative and 0,0-

dirnethyl S-(l,2-dicarbethoxyethyl)dithiophosphate, hereinafter referred to as Malathion. Morev particularly, this invention relates to synergistic insecticidal compositions of these compounds wherein the insecticidal effectiveness of each component is enhanced by the presence of the other to produce an unexpected combined effect.

When two or more substances in combination show an unexpectedly high activity, as for instance, insecticidal activity, the resulting phenomenon is called synergism. The mechanism of synergism is by no means understodd. It is, in fact, quite probable that it differs with different synergistic combinations. The term synergism canibe defined, however, as a cooperative action which istencountered in combinations of two or more biologically active components in whichthe combined activity of t-he two components exceeds the sum of the activities of the components when used alone. 'The insecticidal activity of the mixed components cannot :be predicted from known values of the individual components, but is unpredictable and depends on the individual activity of neither.

It is an object of this invention to provide insecticidal compositions of enhanced killingpower. Another object of this invention is to produce novel compositions containing compounds capable of synergizing the knockdown and killing properties of individual toxic-ants. A further object of this invention is to provide compositionsincluding a relatively toxic phosphorus containinginsecticide in which superior insecticidal activity is obtained because of the synergistic effects, but in which the ultimate toxicity to warm-blooded animals isgreatly reduced because of the lower concentrations of the'phosphorus compounds required when used in combination With the relatively less toxic carbamates. Other objects and advantages of the invention wil-l'rbecome apparent from the description of the invention set forth below.

According to this invention there are provided synergistic insecticidal compositions comprising 0,0.-dimethyl -S-(1,2 dicarbethoxyethyl)dithiophosphateand an organic carbamate ester of the following general formula:

Nooom wherein R is selected from the .group consisting of methyl, ethyl and n-propyl radicals, R isselected from the group consisting of methyl, ethyl and n-propyl'radicals and-R is selected from the group consisting of phenyl, 3-chlorophenyl and 4-chlorophenyl radicals. These car- -bamates may be'prepared as described in 'copending' aptrol of truck crop, forage crop and orchard insects.

The synergistic compositions of this invention can be 2 formulated as aqueous emulsions, as dry or wettable powders, as solutions or in any .othersuitable vehicle. The insecticidal compositions can be utilized as sprays, as "dusts, as aerosol mixtures, insecticidal coating compositions, and as residues. Ingeneral, they can be applied by methods commonly used for control or eradication of insects, mites and the like. Thus these insecticidal compositions can be'formulated with solvents, diluents and carrier media, adhesives, spreading, wetting and emulsifying agents and other ingredients.

"The relative proportions of the active ingredients as well as inert carriers, solvents, dispersants and the like may vary within wide limits.

Thus'the relative proportion (ratio) of the Malathion to the carbamate ester can range from 20 parts of the former per 1 part of the latter to 1 part of the former per 40 parts of the latter and preferably about 1 part of the'former to about2 parts of the latter.

The quantities of the component toxicants in thefinal insecticidal compositions can range from 0.01% to 25.00% for the Malathion and from 0.05% to 50.00% for the carbamate, and preferably from 0.10% to 10.00% for L' the Malathion and from 0.10% to 25.00% for the car- DUST TOWER METHOD This'general method is described in the following reference,.Moore, J. Econ. Ent. 43,-No. 2, 188-190 (1950).

The dusting apparatus consists of a vertical glass cylinder, 34. inches high and 8.5 inches in diameten'into which .the appropriate dust sample is discharged through a small .hole in the center of the cover, by means of a'smal'l laboratory duster operating at an air pressure of 40 p.s.i.g. .The .duster assembly comprises -a 10 ml. beaker, into which the weighed sample is placed, and fitted with a rubber stopper through which pass -the air inlet and dust outlettubes, both of which are made of'% inch diameter copper tubing. At the outer end of the air inlet tubevis 'a trigger valve'that serves as a control for dispensing the dust. The inner'end of this tube reaches nearly to the bottom of the beaker. The end of it 'is sealed but,

-al0ngthe sides, seven 0.032 inch holes are-drilled .at

irregular intervals which serve as air inlets. "Such an arrangement causes pronounced turbulence of'the dust and thus insures exhausting the complete sample from the beaker. The dust outlet tube forms an 'arch from the top of the beaker to the top of the glass dusting tower. After discharge of the sample-into the tower, there is allowed a 2-minute settling time before removal of foliage or insects being treated. A weighed metal'plate is placed in the tower each time a test is made, and" by weighing the amount of dust deposited on it, it is-then possible toealculatethe amount applied per "acre. Because of day-to-day variations in the results obtained by-this test method, comparisons among the individual components and their combinations were made simultaneously in order to'minimize this:source:o'frvari'ation. Y

Slight-modifications in this test employed for specific insect species are as noted below.

Two-spotted spider mite.ln tests on two-spotted mites,

a the mites were confined to in thefield and the cut ends of the stem were wrapped in moist cotton". Individual leaves were then placed in 3.5 inch Petri dishes and dusted as described above. Back treated leaf was then infested with lO last instar squash bug nymphs and the covers of the Petri dishes were replaced. At the end of 24 hours the treated leaves were removed and fresh untreated leaves were introduced into the dishes. Mortality counts were taken after the bugs had been on the untreated leaves for 24 hours.

Mexican bean beetle-In tests using this insect, bean foliage was dusted then infested with fourth instar Mexican bean beetle larvae. These were allowed to feed for 24 hours, then treated foliage was replaced with untreated. Mortality records were made in 48 hours. 7

Harlequin bugL-The foliage was dusted, then infested with harlequin bugs. Mortality counts were taken in 24 hours;

We claim:

1. Synergistic insecticidal compositions comprising 0,0- dimethyl S-(1,2-dicarbethoxyethyl)dithiophosphate and an organic carbamate ester shaving the following general formula:

Nooon wherein R is selected from the group consisting of methyl, ethyl and n-propyl radicals, R is selected from the group consisting of methyl, ethyl and n-propyl radicals and R is selected from the group consisting of phenyl, 3-chlorophenyl and 4-chlorophenyl radicals, wherein said components are present in the ratio of about 2 parts of said carbamate per part of said dithiophosphate. 2. Synergistic insecticidal compositions comprising 0,0- dimethyl S-(l,Z-dicarbethoxyethyl)dithiophosphate and ,3-ch1orophenyl N,N-dimethy] carbamate, said components being present in the ratio of about 2 parts of said carbamate ester to about 1 part of said dithiophosphate.

3. Synergistic insecticidal compositions comprising 0,0- dimethyl S-(1,2-dicarbethoxyethyl)dithiophosphate and phenyl N,N-dimethyl carbamate, said components being Table 1 NGOOR Oarbamates Phosphate Rate Mor- Dust Dust (Lbs Test Method Test Sub ect tallty R 13. R Cone. Name Cone. IA.)

Methyl Methyl- Phenyl 1 I 6.1 Dust Tower Two-spotted Spider Mite"--- 2 Malathiom. 0.5 3.4 do do 13 D do do 1 do 0.5 5 3.2 do 100 Do do do 1 26. 8 Harlequin Bug 0 Malation 0. 5 19. 6 do 20 D do Phenyl 1 do 0.5 20.7 do 95 I Do do 3-Chlorophenyl 1 V 6. 0 Two-spotted Spider Mite"--- 6 Malathion- 0. 5 7. 2 do 28 Do do -dn 1 do 0.5 4.7 on 9s a Do do 4-Ohlorophenyl 1 15.2 Mexican Bean Beetle 0 Malathionn 0. 5 10. 2 do Dn do do 1 -.-do 0.5 6.5 do 80 D 1 5. 1 Two-spotted Spider Mite 6 Malathiom- 0.5 6.4 do 29 ISO D 1 .ign 1 -igufido 1 -....do 0.5 --g0 10g propy opropy t yl 1 o MalathloIL- 0.5 16.6 do 57 Do d do 1 do 0.5 16.6 do 68 Methyl Phenyl IsopropyL. 1 16.4 0 Malathion- 0. 5 20. 7 do 28 D 1 do 0.5 13.2 do 67 D Methyl Phenyl 0. 5 27. 9 Squash Bug 0 Malathion- 0. 25 26. 0 0 I D do 0.5 do 0.25 25.9 do 100 Ethyl Ethy 0.5 49.5 do 0 V Malathion; O. 25 46. 6 do 10 r -Do do 7 0.5 d 0.25 45.4 do 90 do 0. 5 10. 0 Two-spotted Spider Mite"--- 0 Malathion" 0.25 12.0 do 14 Do .-.-do do 0.5 do 0.25 6.5 do 70 n-Propyl n-Propy do 0.5 21.5 do 2 i Malathion 0.25 25.7 do D do y .do 0.5 ..-do 0.25 20.4 do 94 Methyl Phenyl -do 0.5 11.3 on r I Malathiom. 0.25 10.7 do 9 Do do do 0.5 do 0.25 11.2 do 00 D do do 0. 5 53. 3 Squash Bug 0 V Malathlon 0.25 46.6 .-edo p 10 Do do 0.5 do 0.25 46.6 do Do Methyl 3-Ohlurophenyl-.- 1.0 28.4 do 0 V Malathlo 0. 25 27. 8 do 0 Do do do 1.0 do 0.25 28.9 do 100 .Do do 4-Ohlorophenyl 1.0 45.8 do 0 Malathion- 0. 25 46. 6 d o 0 'Do .do do 1.0 do 0.5 47.1 dn 82 The results of the data summarized in Table 1 demonstrate the marked synergism of the insecticidal compositions 'of this invention on a number of insects.

. This application is a division of copending application Serial No. 496,596 filed March 24, 1955, now abandoned, which is a continuation-in-part 'of'Serial No. 427,374, filed May 3, 1954, now abandoned.

'75 bamate ester to about 1 part of said dithiophosphate.

5. Synergistic insecticidal compositions comprising 0,0- dimethyl S-(1,2-dicarbethoxyethyl)dithiophosphate and phenyl N,N-diet.hy1 carbamate, said components being present in the ratio of about 2 parts of said carbamate ester to about 1 part of said dithiophosphate.

'6. Synergistic insecticidal compositions comprising 0,0- dimethyl S-(1,2-dicarbethoxyethyl)dithiophosphate and phenyl N,N-di-n-propyl carbamate, said components being present in the ratio of about 2 parts of said carbamate ester to about 1 part of said dithiophosphate.

7. The method of killing insects which comprises applying to the insects and their habitat a synergistic insecticidal composition comprising 0,0'dimethy1 S-(1,2- dicarbethoxyethyl)-dithiophosphate and an organic carbamate having the general formula NCOOR wherein R is selected from the group consisting of methyl, ethyl and n-propyl radicals, R is selected from the group consisting of methyl, ethyl and n-propyl radicals and R is selected from the group consisting of phenyl, 3-chloropheny1 and 4-chlorophenyl radicals, wherein said components are present in the ratio of about 2 parts of said'carbamate per part of said dithiophos- 5 phate.

References Cited in the file of this patent UNITED STATES PATENTS 10 2,503,390 Jelinek Apr. 11, 1950 2,679,508 Gysin May 25, 1954 OTHER REFERENCES King: U.S.O.A. Handbook No. 69 (May 1954), pp. 15 105-108.

Chemical Age, v01. 63, No. 1631 (1950), p. 540. Sharp: Agr. News Letter, January-February 1952, pp. 1-3.

Roark: U.S. Dept. Agr. Bulletin, E-'344 (May 1935), 20 pp. Z-G.

Frear: Chemistry of the Pesticides, 3rd ed., January 1955, pp. 73-91. 

7. THE METHOD OF KILLING INSECTS WHICH COMPRISES APPLYING TO THE INSECTS AND THEIR HABITAT A SYNERGISTIC INSECTIDAL COMPOSITION COMPRISING O,O-DIMETHYL S-(1,2DICARBETHOXYETHYL)-DITHIOPHOSPHATE AND AN ORGANIC CARBAMATE HAVING THE GENERAL FORMULA 